Terminal block



Sept. 25, 1962 E. R. KULKA 3,055,103

TERMINAL BLOCK Filed Sept. 14, 1959 v 2 Sheets-Sheet 1 FIG I.

' INVENTOR. l7 l3 EUGENE ,9, (04,

krraeA/ United States Patent 3,5,l03 Patented Sept. 25, 1962 free 3,056,103 TEINAL BLGCK Eugene It. Kulka, Mount Vernon, NY, assignor to Kulka Electric Corp, Mount Vernon, N.Y., a corporation of New York Filed Sept. 14, 1959, Ser. No. 839,962 8 Claims. (Cl. 339-198) The present invention relates to improvements in electrical connector devices, and in particular to a 'new and improved terminal block construction.

Terminal blocks are conventionally used to connect one series of conductors electrically with another series of conductors, respectively, to provide pairs of electrically connected conductors. An ideal terminal block will satisfy a number of requirements among which are prevention of arcing between the terminal block and the plate on which it is mounted as well as between the electrically connected pairs of conductors, prevention of accidental touching of the exposed electrical components by personnel, secure assembly of the components of the terminal block, as well as requirements such as high strength, low cost, and ability to accommodate solder lugs or stripped wire leads having no solder lugs.

Up to the present, it has not been possible to effectively fulfill all of these requirements because some of them conflict. For example, a closed bottom wall is essential to prevent arcing to the mounting plate, but this closed bottom wall has so far made impossible a simple secure interconnection of the terminal block components. Embedding portions of electrically conductive plates in the block body by molding the latter onto the electrically conductive portions is extremely expensive and necessitates tap-ping into plastic. Such tapping is difficult to carry out, leaves chips in blind holes, and requires very thick Walls. Using fasteners such as drive rivets to fasten electrically conductive plates to the body of the block results in cracking of the brittle plastic and fails to provide a permanent secure connection.

An object of the present invention is the provision of a terminal block capable of fulfilling all of the above requirements. Another object of the invention is the provision of a terminal block having a molded block body with integral covering plates or walls at the top and bottom thereof.

Still another object of the invention is to provide a terminal block which may include lead identifying indicia which cannot be covered by the leads, which can be made in any desired convenient sizes and of any thermosetting plastics, and which will not require the plastic material to be subjected to the pressure of mounting screws directly engaging the plastic material.

A primary feature of the invention resides in providing eyelet plates having bendable ears crimped into notches of the body of the block to connect the plates securely thereto while at the same time providing the block body With a bottom Wall which is closed beneath the eyelet plates.

Additional objects and advantages of the inventionwill become apparent in the course of the following specification, when taken in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of a terminal block made according to the present invention;

FIG. 2 is a side elevational View of the structure of FIG. 1; 7

FIG. 3 is an exploded view showing an eyelet plate in perspective and the block body in fragmentary perspective;

FIG. 4 is a sectional plan view taken along line 44 of FIG. 2 in the direction of the arrows;

FIG. 5 is a sectional transverse elevation, on an enlarged scale, taken along line 5 of FIG. 2 in the direction of the arrows; and

FIG. 6 is a transverse sectional elevation similar to FIG. 5, but showing a variation in the structure which enables it to accommodate stripped wire leads having no solder lugs.

Referring to FIGS. '1-4, the terminal block of the invention includes an electrically non-conductive body 10 made of Bakelite or any desired thermosetting plastic. The body Ill has a bottom wall Ill and pairs of spaced parallel supporting walls 1-2 extending upwardly from the bottom wall Ill with each pair of walls 12 located between and being integral with a pair of additional walls 1'3. The walls I3 extend upwardly beyond the top supporting surfaces 14 of walls 12 as well as beyond the end faces 15 of the walls 12, each of these end faces being formed with a notch 16. The upper surfaces 17 (FIG. 5) of the notches 16 are directed away from support surfaces 14 downwardly toward bottom Wall 11, so that each wall 12 has at least one pair of surfaces 14 and 17 directed away from each other for a purpose pointed out below.

The body Ill is completed by a top wall 18 extending between the walls 13 over the surfaces 14. Thus, the body Ill is formed between its top wall 18 and bottom wall 1d with a row of cells 19 extending through the body 10 from one side to the opposite side thereof, and each cell 19 has an elongated portion of T-shaped cross section (FIG. 2) terminating short of the ends of the cell in end faces 1'5 which are respectively formed with the notches 16. The support surfaces 14 are located in each cell 19 at the junction between the lower narrow portion 20 and upper wider portion 2-1 of the cell, and the top wall 18 is formed with a pair of openings 22 aligned with the narrow portion '20 of each cell 19.

The body It) is molded in lengths much longer than indicated in FIGS. 1, 2, and 4 and then is cut into suitable lengths as shown in FIGS. 1, 2, and 4. The bottom wall 11 has relatively thin circular portions 23 (FIG. 5) respectively aligned beneath openings 22 and adapted to be drilled or punched out only at the end cells l9 of the row of cells so as to form the bottom wall openings 24 (FIG. 1) for a purpose pointed out below.

The pair of support surfaces 14 in each cell 19 (except the end cells) carry an elongated eyelet plate 25 made of brass, for example, and stamped so as to have, before assembly with the body 10, the configuration shown in FIG. 3. The eyelet plate 25 has at each of its ends a pair of bendable ears 26 and between its ends a pair of internally threaded eyelets 27 threaded along their entire length. A pair of screws 28 are threadedly carried by the eyelets 27, respectively, of each eyelet plate 25. The width of the eyelet plate is substantially equal to the width of the upper portion 21 of each cell 19. Before assembly with body 10, the ears 26 at one end of eyelet plate 25 are preformed to extend downwardly at a right angle to the adjoining plate portion and terminate in tips 29 extending at to the adjoining portions of cars 26, as shown in FIG. 3.

The assembling is carried out very simply and quickly by slipping eyelet plates 25 into all cells 19 except the end cells from the same side of body 10 so that the plates 25 engage surfaces 14 and the eyelets 27 become located in the lower portions 20 of the cells. In this position, the pre-formed cars 26 at one end of the eyelet plate 25 extend into the adjacent notches 16 at one side of the body Ill and the bent tips 29 engage the surfaces 17 of said notches 16. The assembly with the fixture is then positioned so as to render the straight cars 26 at the other side of body 10 accessible to a suitable crimping tool which is applied to these ears to crimp them into'the adjoining notches 16 against the surfaces 17 thereof with the ears extending along and engaging the parts of end faces 15 which extend between surfaces 14 and 17. The assembly is now complete. Since the surfaces 14 and 17 are directed away from each other, the eyelet plates 25 are securely fixed to the body 18, the ears or extensions 26 of the plates 25 forming a means which fixes the eyelet plates to the body 10, which is located only at the exterior of the body 10, and which engages only exterior surfaces thereof.

The manner in which spade lugs 30 are connected to the eyelet plates is apparent from FIG. 5. A screw driver extending through an opening 22 can cooperate with the head 31 of a screw 28 to turn the latter, and the openings 22 are larger than heads 31 so that they can turn freely in openings 22. When a solder lug 30 is slipped beneath head 31 of a screw 28, the latter can be tightened down onto the lug. Since the entire length of the eyelets 27 are available for carrying screws 28, the eyelets 27 can be relatively short.

To accommodate stripped wire ends 32 (FIG. 6), a pressure plate 33 may be placed between eyelet plate 25 and screw heads 31 with the screw shanks extending freely through openings of pressure plate 33. This plate has serrated surface portions 34 directed toward plate 25 and engaging wire 32. The screws of FIG. 6 can be turned down with a force sufficient to flatten wire 32 into an elliptical cross section to provide a relatively large area of contact. Plates 33 have a width equal to that of eyelet plates 25.

Plates 40, identical with eyelet plates 25, except that they have no eyelet portions, are provided to fortify the end mounting portions of the terminal blocks. These plates 40 are shown in FIGS. 1, 2 and 4, and for convenience are illustrated only at the right-hand end of each view, it being understood, however, that in practice a plate is employed at each end of the terminal block.

Each plate 40 has at each end a pair of bendable ears 42, and intermediate its ends a pair of mounting holes 41. The plates 40 are placed in the end cells 19 on surfaces 14 thereof straddling the lower portions 20 of the cells with the mounting holes 41 in registry with the bottom wall openings 24, and the ears 42 are bent into the notches 16, as previously described, to secure the plates 40 in mounted position. When the terminal block is to be mounted, mounting screws are passed through the plate mounting holes 41 and the aligned mounting holes 24 of the block body. These mounting screws do not directly engage body and instead press the plates 40 against the relatively large areas of surfaces 14 so that a considerable force can be applied without unduly stressing the body 10.

It will be noted that all exterior surfaces of body 10 are located outwardly beyond screws 28, eyelt plates 25, and pressure plate 33 in the case of FIG. 6, and the openings at the ends of cells 19 as Well as the openings 22 are too small to allow a human finger to have access to the electrically conductive elements. Also bottom wall 11 is entirely closed beneath eyelet plates 25, so that there can be no arcing to the mounting plate. With the structure of the invention there are no fastener extending into body 10 to crack the latter.

The upper surface of top wall 18 can be embossed, printed or otherwise provided with lead-identifying indicia which cannot be covered by the leads. This enables the various terminals to be identified and distinguished without the necessity for separate marking strips which are customarily used for this purpose.

While a preferred embodiment of the invention has been shown and described herein, it is obvious that numerous omissions, change and additions may be made therein without departing from the spirit and scope of the invention.

What I claim is:

1. A terminal block comprising an elongated electrically non-conductive body having top and bottom walls and formed between said walls with a row of hollow cells each extending laterally through said body from one side to the opposite side thereof and each cell having between its ends an elongated portion of T-shaped cross section terminating short of said ends in end surfaces each of which is formed with a notch, in combination with a plurality of electrically conducting plates secured within said cells, said plates having deformably opposed end portions sized to be received within said notches to hold said plates within said cells, said top wall being formed with a pair of openings aligned with the lower narrower portion of each cell to provide access to said plates.

2. A terminal block as recited in claim 1 and wherein said bottom wall, at the end cells of said row, is formed with terminal block mounting openings which are aligned with said top wall opening, and wherein each end cell has, at the junction between said upper and lower portions, a pair of supporting surfaces directed toward said top wall, and a pair of mounting plates in said end cells substantially as wide as said upper portions thereof on said supporting surfaces thereof bridging said narrow cell portions and formed with openings respectively aligned with the top wall openings over said end cells, so that screws accessible through said top wall opening can extend through said plate and bottom wall openings into a mounting member and press said plates onto said supporting surfaces of said end cells to fix said body to said mounting member.

3. A terminal block as recited in claim 1 and wherein each cell has at the junction between its lower and upper portions a pair of support surfaces directed toward said top wall, said plates having a width substantially equal to the width of said upper cell portions, said plates resting on said support surfaces, bridging the lower cell portions,

' and having ears extending respectively into said notches,

said eyelet plates being formed with a pair of threaded openings in line with said top wall opening.

4. A terminal block to secure a lead to a terminal screw comprising a non-conductive elongated body and a plurality of conductive plates, said body being formed with a bottom wall, a top wall and a plurality of dividing walls transverse thereto which define a plurality of elongated cells transverse to said block, each of said cells including a pair of upwardly facing supporting surfaces within said body and within the confines of said cells. securement notches formed at opposite ends of each of said cells having downwardly facing securement surfaces, said plates being substantially of the width of said cells and of a length less than the length of said cells and having ears extending therefrom adapted to be engaged with said securement notches to secure said plate to said block, said plates being formed with at least one threaded hole, said terminal screws received therein, said top wall being formed with clearance openings a igned with said threaded holes to provide access to said terminal screw on said securement plates, connection of said lead to said terminal screws being made through the opened ends of said cells.

5. A terminal block for securing a lead to a terminal screw comprising a non-conductive elongated body and a plurality of conductive plates, said body being formed with a bottom wall, a top wall and a plurality of dividing walls transverse thereto which define a plurality of elongated cells transverse to said block, each of said cells including a pair of supporting walls located parallel to and against said aforementioned dividing walls which provide supporting surfaces on their upper surfaces, said supporting walls terminating inwardly of the ends of said cells at end faces which are formed with securement notches, said plates being substantially of the width of said cells and of the length of said supporting walls and having ears extending from their ends adapted to be engaged with said supporting wall securement notches to secure said plates to said block, said plates being formed with at least one threaded hole, said terminal screw rcceived therein, said top wall being formed with clearance openings aligned with said threaded holes to provide access to said terminal screws on said securement plates, connection being made from said lead to said terminal screw through the open ends of said cells.

6. A terminal block according to claim 5 adapted to be mounted :by a mounting screw onto a surface wherein the end cells of said terminal block are formed with securement openings in the bottom wall in alignment with said clearance openings in said top wall and wherein said plates located in said end cells are formed with screw receiving holes of a diameter less than that of said top wall clearance holes and adapted to receive said mounting screw to mount said block onto said mounting surface.

7. A terminal block for securing a lead to a terminal screw comprising a non-conductive terminal block body and a conductive plate, said body being formed with a bottom wall, a top wall, and at least two dividing walls transverse thereto which define an elongated cell transverse to said terminal block body, said cell including a pair of supporting walls located parallel to and adjacent said aforementioned dividing walls and providing upwardly facing supporting surfaces, said supporting walls terminating inwardly of the ends of said cell at end faces, at least one securement notch formed in each end of said cell within said end faces, said conductive plate being substantially of the width of said cell and of the length of said supporting walls and having at least one ear formed at either end adapted to be engaged within said securement notches to secure said plate to said block,

said plate being formed with at least one threaded hole, said terminal screw received therein, said top wall being formed with at least one clearance opening aligned with said threaded hole to provide access to said terminal screw, connection being made from said lead to said terminal screw through the open ends of said cell.

8. A terminal block according to claim 7 adapted to be mounted by mounting screws into a surface wherein two end cells are formed within said block, securement openings formed in the bottom wall of said end ce ls in alignment with said clearance openings in said top wall, and wherein said plates located in said end cells are formed with screw receiving holes of a diameter less than that of said top wall clearance holes and adapted to receive said mounting screws to mount said block on said mounting surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 2,189,622 Barnsteiner Feb. 6, 1940 2,221,710 Johnson Nov. 12, 1940 2,463,826 Thacker Mar. 8, 1949 2,679,634 Rawley May 25, 1954 2,693,586 Dorfman et al. Nov. 2, 1954 2,724,811 Poupitch Nov. 22, 1955 FOREIGN PATENTS 661,389 Germany June 17, 1938 823,154 Germany Dec. 3, 1951 

